Title: Mid-Semester Lecture Exam
1Mid-Semester Lecture Exam
- Vocabulary
- Obvious steps within GIS
- Selection and query processes
- Working with tables
- Classification concepts
- Projections
- What are they what do they change
- Coordinates how are they relevant
2Home Work 1
Dealing with an exchange format
- In ArcToolBox
- Coversion Tools
- Import to coverage
- Import from interchange file
- Define projection for coverage
- In ArcMap
- Data
- Export to shapefile
- Project shapefile to whatever you want
3- Data types raster vs. vector
- How does GIS differ from a mapping or CAD package
- The three basic components of ArcGIS
- Define vs Projection
- Metadata
- More questions about coordinates
- What information is critical for a coordinates to
be relevant? - Cardinality
- When do you use a join and when relate?
4Tables Continued
- Adding Fields and Records
5There are several data types
- There are two basic types common used
6Data Types
It is very important to choose the right data
type.
7ArcGIS can handle several tabular data formats
- Coverages use an INFO format. These are an older
format, cumbersome, but still frequently used. - A shapefile uses a .dbf format. Much more
sophisticated than an INFO file. We are
currently using .dbf files in the lab exercises. - Geodatabases uses a RDBMS format. Very
sophisticated and powerful but more complex. We
will use them in a few weeks time.
8Very often you need a new field in a table.
9Specify the Name and the Data Type
Integers No Decimals
-32,000 to 32,000
-2 billion to 2 billion
10Numbers with Decimal Places
Precision is the number of digits to be stored.
Scale is the number of decimal places.
11Date
Text
It is important to specify a length to
accommodate your attribute but not too long.
12Calculating a Value
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14The selected records are assigned the calculated
value
Notice that text values are enclosed in double
quotes
15Calculating a Numeric
16Convert from one data type to a different data
type
Text type
Numeric type
17Add a new numeric FIPS field then calculate the
text field as a numeric field.
18Create a New Table
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20Open the new table in ArcMap and then add data
21You can use ascii files